Disk controller configured to perform out of order execution of write operations

Abstract

A hard disk unit includes a disk, controller microprocessor, host bus interface, buffer memory, buffer memory controller and disk formatter. The bus interface receives write operations, and the corresponding write operation data is stored in the buffer memory. The buffer memory controller also includes a set of address registers and a set of block count registers. The microprocessor loads the address registers with the buffer memory addresses of data of multiple write operations and loads the block count registers with the size of the corresponding data. The microprocessor then issues a single command to the buffer memory controller to transfer the data from the buffer memory to the disk formatter. The address registers and block count registers enable the data of multiple write operations to be transferred and written to a disk in an order other than the order in which the write operations were received at the bus interface.

Description

1. Field of the InventionThis invention relates generally to hard disk controllers and, more particularly, the invention relates to a disk controller and associated methods that enable multiple write operations to be executed out of order during a single revolution of a disk.2. Description of the Related ArtThe speed at which a hard disk drive executes read and write operations requested by a host computer is critical to the performance of the computer. Any delay caused by the hard disk drive will likely cause a corresponding delay in the execution of a program by the computer. Some of the developments in hard drive technology have focused on decreasing the response time or increasing the data transfer rate for individual disk operations. Other developments in hard drive technology have focused on decreasing the amount of time that it takes to execute multiple operations. Two of the latter type of developments are described in U.S. Pat. Nos. 4,667,286 and 6,029,226.U.S. Pat. No. 4,6...

AI Technical Summary

Problems solved by technology

Any delay caused by the hard disk drive will likely cause a corresponding delay in the execution of a program by the computer.

The microprocessor is typically not fast enough to issue a second or additional commands to the buffer controller in time to supply the data for a second or additional operations without losing a revolution of the disk in the meantime.

Typically, by the time the microprocessor sets up the buffer memory controller and issues the additional command, the sector to be written has passed the write head and a revolution of the disk is lost.

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